A rotating electrical machine mounted in a vehicle such as an automobile has a rotor, and a stator provided on a periphery of the rotor. The rotating electrical machine is used as a motor or generator, and is used so that a rotational force is generated in the rotor by a current being caused to flow into the stator in a case of a motor, and so that current flowing into the stator owing to a rotation of the rotor is extracted in a case of a generator. Further, when a large output is generated in the rotating electrical machine, heat generated by the rotor and stator of the rotating electrical machine increases. When temperatures of the rotor and stator rise, a problem such as a decrease in magnetic force of the rotor or an insulation failure in the stator occurs.
Because of this, a cooling structure is employed in the rotating electrical machine. A structure such that a cooling medium passing from a pump through an interior of the rotor is jetted onto the stator, cooling the rotor and stator, is known as a rotating electrical machine cooling structure (Patent Document 1). Also, a configuration such that cooling of both of two rotating electrical machines, those being a generator of a hybrid vehicle-use drive device and an electric motor, is carried out using one pump has been proposed (Patent Document 2).
In the case of the cooling structure wherein the cooling medium that passes through the interior of the rotor is jetted onto the stator, a configuration is such that, in order to simplify the structure as far as possible, the cooling medium is jetted onto the stator utilizing centrifugal force generated by the rotation of the rotor.
Also, in the case of the hybrid vehicle-use drive device, optimization of a path of a cooling medium for carrying out cooling of not only the generator but also the electric motor, and of a position in which the cooling medium is stored, has been proposed.